Adsorptive separation systems are known for use in separation of gas streams comprising multiple gas components. Pressure swing, temperature swing, and partial pressure swing or displacement purge adsorption are exemplary processes known in the art for performing such separations of multi-component gas mixtures. In the exemplary case of separation of methane-containing gas mixtures, existing adsorption based separation processes do not provide for desirably efficient separation of methane from other gas components. Existing adsorptive methane separation processes typically include sequential pressure or temperature swing adsorption systems requiring multiple adsorption steps and corresponding multiple adsorption systems or subsystems, and typically result in the delivery of product methane gas streams at relatively low pressure, commonly as a component of desorption exhaust. Existing processes may also result in delivery of methane product gas at relatively low purity and/or recovery due to the lack of efficiency in adsorptively separating methane from other common gas mixture components. Such other common gas mixture components may for example comprise carbon dioxide, nitrogen and oxygen in impure methane-containing feed gas streams. Examples of such impure methane-containing gas streams may include biogas, landfill gas, impure natural gas or other methane-containing commercial gas streams. In applications where such impure methane streams are desired to be stored and used as compressed or liquified gas fuels, the relatively low purity of the methane product streams typically produced by some existing adsorptive separation processes may result in inefficiencies and/or impracticalities in the compression and/or liquifaction processes used to store such fuel gases.